<template>
  <view class="canvasBox">
    <template v-if="isUse">
      <view class="box">
        <view class="line"></view>
        <view class="angle"></view>
      </view>
      <view class="box2" v-if="isUseTorch">
        <view class="track" @click="openTrack">
          <svg t="1653920715959" class="icon" viewBox="0 0 1024 1024" version="1.1" xmlns="http://www.w3.org/2000/svg"
            p-id="1351" width="32" height="32">
            <path
              d="M651.353043 550.479503H378.752795L240.862609 364.315031c-3.688944-4.897391-5.660621-10.876025-5.660621-17.045466v-60.040745c0-15.773416 12.847702-28.621118 28.621118-28.621118h502.459627c15.773416 0 28.621118 12.847702 28.621118 28.621118v59.977143c0 6.105839-1.971677 12.084472-5.660621 17.045466l-137.890187 186.228074zM378.752795 598.308571v398.024348c0 15.328199 12.402484 27.667081 27.667081 27.667081h217.266087c15.328199 0 27.667081-12.402484 27.66708-27.667081V598.308571H378.752795z m136.300124 176.942112c-14.564969 0-26.331429-11.76646-26.331428-26.331428v-81.283975c0-14.564969 11.76646-26.331429 26.331428-26.331429 14.564969 0 26.331429 11.76646 26.331429 26.331429v81.283975c0 14.564969-11.76646 26.331429-26.331429 26.331428zM512 222.608696c-17.554286 0-31.801242-14.246957-31.801242-31.801243V31.801242c0-17.554286 14.246957-31.801242 31.801242-31.801242s31.801242 14.246957 31.801242 31.801242v159.006211c0 17.554286-14.246957 31.801242-31.801242 31.801243zM280.932174 205.881242c-9.47677 0-18.889938-4.197764-25.122981-12.275279L158.242981 67.991056a31.864845 31.864845 0 0 1 5.597019-44.648944 31.864845 31.864845 0 0 1 44.648944 5.597018l97.502609 125.551305a31.864845 31.864845 0 0 1-5.597019 44.648944c-5.787826 4.579379-12.656894 6.741863-19.46236 6.741863zM723.987081 205.881242c-6.805466 0-13.674534-2.162484-19.462361-6.678261a31.794882 31.794882 0 0 1-5.597018-44.648944l97.566211-125.551304a31.794882 31.794882 0 0 1 44.648944-5.597019 31.794882 31.794882 0 0 1 5.597019 44.648944l-97.566211 125.551305c-6.360248 8.077516-15.709814 12.27528-25.186584 12.275279z"
              fill="#ffffff" p-id="1352"></path>
          </svg>
          {{ trackStatus ? '关闭闪光灯' : '打开闪光灯' }}
        </view>
      </view>

      <view class="mask1 mask" :style="'height:' + maskHeight + 'px;'"></view>
      <view class="mask2 mask"
        :style="'width:' + maskWidth + 'px;top:' + maskHeight + 'px;height:' + canvasHeight + 'px'"></view>
      <view class="mask3 mask" :style="'height:' + maskHeight + 'px;'"></view>
      <view class="mask4 mask"
        :style="'width:' + maskWidth + 'px;top:' + maskHeight + 'px;height:' + canvasHeight + 'px'"></view>
    </template>
    <template v-else>
      <slot name="error">
        <view class="error">
          <view class="on1">相机权限被拒绝，请尝试如下操作：</view>
          <view>· 刷新页面后重试；</view>
          <view>· 在系统中检测当前App或浏览器的相机权限是否被禁用；</view>
          <view>· 如果依然不能体验，建议在微信中打开链接；</view>
        </view>
      </slot>
    </template>
  </view>
</template>

<script>
import jsQR from "jsqr"

export default {
  props: {
    continue: {
      type: Boolean,
      default: true // false 监听一次   true 持续监听
    },
    exact: {
      type: String,
      default: 'environment' // environment 后摄像头  user 前摄像头
    },
    size: {
      type: String,
      default: 'whole' // whole 全屏  balf 半屏
    },
    definition: {
      type: Boolean,
      default: false // fasle 正常  true 高清
    }
  },
  data() {
    return {
      windowWidth: 0,
      windowHeight: 0,
      video: null,
      canvas2d: null,
      canvas2d2: null,
      canvasWidth: 200,
      canvasHeight: 200,
      maskWidth: 0,
      maskHeight: 0,
      inter: 0,

      track: null,
      isUseTorch: false,
      trackStatus: false,

      isParse: false,
      isUse: true
    }
  },
  mounted() {
    if (origin.indexOf('https') === -1) throw '请在 https 环境中使用摄像头组件。'
    this.windowWidth = document.documentElement.clientWidth || document.body.clientWidth
    this.windowHeight = document.documentElement.clientHeight || document.body.clientHeight
    this.windowHeight = this.size === 'whole' ? this.windowHeight : this.windowHeight / 2
    this.isParse = true

    this.$nextTick(() => {
      this.createMsk()
      this.openScan()
    })
  },
  // destroyed() {
  // 	this.closeCamera()
  // },
  methods: {
    openScan() {
      const width = this.transtion(this.windowHeight)
      const height = this.transtion(this.windowWidth)
      const videoParam = {
        audio: false,
        video: {
          facingMode: { exact: this.exact },
          width,
          height
        }
      }
      navigator.mediaDevices
        .getUserMedia(videoParam)
        .then(stream => {
          this.video = document.createElement('video')
          this.video.width = this.windowWidth
          this.video.height = this.windowHeight

          const canvas = document.createElement('canvas')
          canvas.id = 'canvas'
          canvas.width = this.transtion(this.canvasWidth)
          canvas.height = this.transtion(this.canvasHeight)
          canvas.style = 'display:none;'
          //canvas.style = 'position: fixed;top: 0;z-index: 999;left:0'
          this.canvas2d = canvas.getContext('2d')

          // 设置当前宽高 满屏
          const canvasBox = document.querySelector('.canvasBox')
          canvasBox.append(this.video)
          canvasBox.append(canvas)
          canvasBox.style = `width:${this.windowWidth}px;height:${this.windowHeight}px;`

          // 创建第二个canvas
          const canvas2 = document.createElement('canvas')
          canvas2.id = 'canvas2'
          canvas2.width = this.canvasWidth
          canvas2.height = this.canvasHeight
          canvas2.style = 'position: absolute;top: 50%;left: 50%;z-index: 20;transform: translate(-50%,100%);'
          this.canvas2d2 = canvas2.getContext('2d')
          canvasBox.append(canvas2)

          this.video.srcObject = stream
          this.video.setAttribute('playsinline', true)
          this.video.play()
          this.tick()

          this.track = stream.getVideoTracks()[0]
          setTimeout(() => {
            this.isUseTorch = this.track.getCapabilities().torch || null
          }, 500)
        })
        .catch(err => {
          this.isUse = false
          this.$emit('error', err)
        })
    },

    closeCamera() {
      this.isParse = false
      if (this.video && this.video.srcObject) {
        this.video.srcObject.getTracks().forEach(track => {
          track.stop()
        })
      }
    },

    tick() {
      if (!this.isParse) return
      if (this.video.readyState === this.video.HAVE_ENOUGH_DATA) {
        this.canvas2d.drawImage(
          this.video,
          this.transtion(this.maskWidth),
          this.transtion(this.maskHeight),
          this.transtion(200),
          this.transtion(200),
          0,
          0,
          this.transtion(this.canvasWidth),
          this.transtion(this.canvasHeight)
        )

        const imageData = this.canvas2d.getImageData(
          0,
          0,
          this.transtion(this.canvasWidth),
          this.transtion(this.canvasHeight)
        )

        const code = jsQR(imageData.data, imageData.width, imageData.height, {
          inversionAttempts: 'dontInvert'
        })

        this.canvas2d2.clearRect(0, 0, this.canvasWidth, this.canvasHeight)
        if (code) {
          this.drawLine(code.location.topLeftCorner, code.location.topRightCorner)
          this.drawLine(code.location.topRightCorner, code.location.bottomRightCorner)
          this.drawLine(code.location.bottomRightCorner, code.location.bottomLeftCorner)
          this.drawLine(code.location.bottomLeftCorner, code.location.topLeftCorner)
          if (code.data) {
            this.getData(code.data)
          }
        }
      }
      requestAnimationFrame(this.tick)
    },
    drawLine(begin, end, color = '#FF3B58') {
      this.canvas2d2.beginPath()
      this.canvas2d2.moveTo(this.nutranstion(begin.x), this.nutranstion(begin.y))
      this.canvas2d2.lineTo(this.nutranstion(end.x), this.nutranstion(end.y))
      this.canvas2d2.lineWidth = 4
      this.canvas2d2.strokeStyle = color
      this.canvas2d2.stroke()
    },

    getData(data) {
      this.sacnSuccess = true
      this.$emit('success', data)
      if (!this.continue) {
        this.closeCamera()
      }
    },

    openTrack() {
      this.trackStatus = !this.trackStatus
      this.track.applyConstraints({
        advanced: [{ torch: this.trackStatus }]
      })
    },

    createMsk() {
      this.maskWidth = this.windowWidth / 2 - this.canvasWidth / 2
      this.maskHeight = this.windowHeight / 2 - this.canvasHeight / 2
    },

    transtion(number) {
      return this.definition ? number * 2.8 : number * 1.8
    },
    nutranstion(number) {
      return this.definition ? number / 2.8 : number / 1.8
    }
  }
}
</script>

<style scoped>
/* page {
	background-color: #333333;
} */

.canvasBox {
  width: 100vw;
  height: 100vh;
  position: relative;

  /* background-image: linear-gradient(
			0deg,
			transparent 24%,
			rgba(32, 255, 77, 0.1) 25%,
			rgba(32, 255, 77, 0.1) 26%,
			transparent 27%,
			transparent 74%,
			rgba(32, 255, 77, 0.1) 75%,
			rgba(32, 255, 77, 0.1) 76%,
			transparent 77%,
			transparent
		),
		linear-gradient(
			90deg,
			transparent 24%,
			rgba(32, 255, 77, 0.1) 25%,
			rgba(32, 255, 77, 0.1) 26%,
			transparent 27%,
			transparent 74%,
			rgba(32, 255, 77, 0.1) 75%,
			rgba(32, 255, 77, 0.1) 76%,
			transparent 77%,
			transparent
		);
	background-size: 3rem 3rem;
	background-position: -1rem -1rem;
	z-index: 10;
	background-color: #1110; */
}

.box {
  width: 200px;
  height: 200px;
  position: absolute;
  left: 50%;
  top: -50%;
  transform: translate(-50%, -200%);
  overflow: hidden;
  border: 0.1rem solid rgba(100, 156, 155, 0.2);
  z-index: 11;
}

.line {
  height: calc(100% - 2px);
  width: 100%;
  background: linear-gradient(180deg, rgba(0, 255, 51, 0) 43%, rgb(100, 156, 155) 211%);
  border-bottom: 3px solid #649c9b;
  transform: translateY(-100%);
  animation: radar-beam 2s infinite alternate;
  animation-timing-function: cubic-bezier(0.53, 0, 0.43, 0.99);
  animation-delay: 1.4s;
}

.box:after,
.box:before,
.angle:after,
.angle:before {
  content: '';
  display: block;
  position: absolute;
  width: 3vw;
  height: 3vw;
  z-index: 12;
  border: 0.2rem solid transparent;
}

.box:after,
.box:before {
  top: 0;
  border-top-color: #649c9b;
}

.angle:after,
.angle:before {
  bottom: 0;
  border-bottom-color: #649c9b;
}

.box:before,
.angle:before {
  left: 0;
  border-left-color: #649c9b;
}

.box:after,
.angle:after {
  right: 0;
  border-right-color: #649c9b;
}

@keyframes radar-beam {
  0% {
    transform: translateY(-100%);
  }

  100% {
    transform: translateY(0);
  }
}

.msg {
  text-align: center;
  padding: 20rpx 0;
}

.box2 {
  width: 300px;
  height: 200px;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 20;
}

.track {
  position: absolute;
  bottom: -100px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 20;
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.mask {
  position: absolute;
  z-index: 10;
  background-color: rgba(0, 0, 0, 0.55);
}

.mask1 {
  top: 0;
  left: 0;
  right: 0;
}

.mask2 {
  right: 0;
}

.mask3 {
  right: 0;
  left: 0;
  bottom: 0;
}

.mask4 {
  left: 0;
}

.error {
  color: #fff;
  padding: 40rpx;
  font-size: 24rpx;
  background-color: #333333;
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 550rpx;
  border-radius: 20rpx;
}

.error .on1 {
  font-size: 30rpx;
}
</style>

